More On Cars:

Dear Esther,
Using nitrogen in tires will not cause a drop in gas mileage. Have you checked your tire pressure lately? The most probable reason for the drop in fuel economy is that your tire pressure is low. Just because you replaced the air in your tires with nitrogen does not mean you no longer need to check your tire pressure.

While nitrogen in tires does equate to a slower loss of pressure, your tire pressure will still decrease over time, which translates to a loss in fuel economy. Check your tire pressure, and make sure that it is at the recommended pounds-per-square-inch level, which is listed in your owner's manual or on the label on the driver's side doorjamb, refilling your tires with nitrogen or air if necessary.

If you have a car shop refill your tires, immediately confirm that the pressure is set to the recommended level. Ask the shop to adjust the pressure if it's not at the level. Check your tire pressure once a month to maintain optimum pressure.

Get more news, money-saving tips and expert advice by signing up for a free Bankrate newsletter.

Ask the adviser

Bankrate's content, including the guidance of its advice-and-expert columns and this website, is intended only to assist you with financial decisions. The content is broad in scope and does not consider your personal financial situation. Bankrate recommends that you seek the advice of advisers who are fully aware of your individual circumstances before making any final decisions or implementing any financial strategy. Please remember that your use of this website is governed by Bankrate's Terms of Use.

Tara Baukus Mello writes Bankrate's cars blog as well as the weekly Driving for Dollars column, providing both practical financial advice for consumers as well as insight into the latest developments in the automotive world.

Bankrate wants to hear from you and encourages thoughtful and constructive comments. We ask that you stay focused on the story topic, respect other people's opinions, and avoid profanity, offensive statements, illegal contents and advertisement posts. Comments are not reviewed before they are posted. Bankrate reserves the right (but is not obligated) to edit or delete your comments. Please avoid posting private or confidential information, and also keep in mind that anything you post may be disclosed, published, transmitted or reused. We do not permit the inclusion of hyperlinks in comments and may remove any comment that includes a hyperlink.

While gas prices have dropped dramatically, the sales of diesel cars has continued to grow, rising 13.5 percent in 2014 over 2013, according to the latest data compiled by IHS Automotive for the Diesel Technology Forum.
... Read more

Bankrate.com is an independent, advertising-supported publisher and comparison service. Bankrate may be compensated in exchange for featured placement of certain sponsored products and services, or your clicking on certain links posted on this website.